Device for spiral stitching



Jan. 17, 1956 H. M. Ross ET AL DEVICE FOR SPIRAL STITCHING 4 Sheets-Sheet 1 Filed July 15, 1953 If .E'.

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Jan. 17, 1956 H. M. ROSS ETAL DEVICE FOR SPIRAL STITCHING 4 Sheets-Sheet 2 Filed July 15, 1955 INVE NTOR flare/444170;:

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Jan. 17, 1956 H. M. Ross ETAL 2,730,974

DEVICE FOR SPIRAL STITCHING Filed July 15, 1953 4 Sheets-Sheet 3 INVENTURS Hero/d 44- fax: Kobe/'2 (o'wen Jan. 17, 1956 H. M, ROSS ET AL DEVICE FOR SPIRAL STITCHING INVENTOR HAROLD M. ROSS ROBERT COWEN ATTY.

United States Patent DEVICE FOR SPRAL STITCH-ENG Harold M. Ross and Robert Cowen, Toronto, ()ntario, Canada; said Cowen assignor to Century Engineering Company, Toronto, Ontario, Canada Application July 15, 1953, Serial No. 368,122

18 Claims. (Cl. 112---2) This invention relates to improvements in devices adapted for use with sewing machines for carrying out spiral stitching.

In sewing machine attachments of this type it is the usual practise to mount the fabric being stitched on a slide movable relative to the needle of the machine and to employ a worm arrangement driven from the feed mechanism of the machine to drive the slide towards or away from the needle in accordance with the movement of the worm wheel member.

As the length of each revolution of the spiral increases in proportion to its increasing radius it will be appreciated that the slide movement relative the needle must be nonlinear to provide uniform radial spacing between successive rows of the spiral stitching.

This requirement of uniform spacing has many fields of application but it is of particular importance in the garment industry in the forming of the bust cups, brassieres or the like wherein spiral stitching is employed, and for appearance and optimum form the successive spiral convolutions must be precisely equally spaced throughout the cup.

We have found that the present arrangement of a slide operated to move with a worm member will not give sufiiciently precise slide movement to provide the uniformity of stitching and precisely accurate spacing which is so highly desirable in the formation of such items as bust cups, brassieres and the like.

The object of the present invention therefore is to provide a device which will cause the fabric being spirally stitched to move relative the stitching needle in such a controlled manner as to provide precise uniformity of spacing between the successive convolutions of the spiralling stitching.

A further important object is to provide a device as aforesaid as an economical attachment to a conventional sewing machine, which attachment will be simple and convenient to operate.

Another important object is to enable the fabric being stitched to be held in such a manner that it will freely follow the movement imparted thereto by the sewing machine in stitchting and will also be free to conform to the shape into which the spiral stitchting draws the fabric while being maintained free from contact with any portion of the device which would be liable to mark or soil the fabric.

Still another object is to provide a device as aforesaid which will be of rugged and economical construction and will operate smoothly and efficiently with a minimum of maintenance requirements.

The principal feature of the invention resides in controlling the movement of the fabric-carrying slide by means of a cam having a precisely determined, generally spiral shaped camming surface and rotated to have a constant peripheral velocity at the point of engagement with the slide to impart the requisite non-linear movement to the slide with precision accuracy.

2,730,974 Patented Jan. 17, 1956 More particularly, according to the invention, the cam is provided with a sprocket chain or the like mounted on its shaped periphery, and the slide includes a sprocket wheel or corresponding element engaging with the chain and driving the cam through the chain to impart uniform peripheral speed thereto while the movement of the slide is effected through the displacement of the sprocket by the cam it drives in accordance with the peripheral configuration of the cam.

Another feature of the invention resides in driving the slide-carried sprocket wheel through a rocker and clutch mechanism from the feed mechanism of the driving machine to maintain positive cam rotation independent of the position of the slide.

Still another feature resides in providing an arrangement of rollers mounting the slide for smooth uniform movement.

Another important feature resides in providing a pin on the slide on which the fabric being stitched is adapted to be impaled, and arranging a system of air jets to retain the fabric in position for stitchting and yieldingly hold the same to the configuration naturally assumed on stitching without the necessity of positively gripping, holding or handling the fabric throughout the stitching.

In the particular application of spirally stitching bust cups the fabric is impaled at the centre and the air jets are directed, one from the centre outwardly along the fabric to hold the fabric open, and one generally tangentially at the periphery of the fabric to flatten the fabric at the point of stitching.

Another feature of the invention resides in building into the cam an adjustable control to automatically regulate the radial extent of the spiral stitching.

These and other objects and features will become apparent from the following description taken in conjunction with the accompanying drawings in which,

Figure 1 is a plan view of the attachment constructed in accordance with the invention.

Figure 2 is a vertical section on the line 22 of Figure 1 showing the attachment principally in front elevation.

Figure 3 is an end elevation of the device of Figures 1 and 2 with parts being broken away.

Figure 4 is a reduced plan view of the device showing it in relation to a sewing machine.

Figure 5 is an enlarged fragmentary perspective View illustrating the manner of supporting a work or fabric relative the operating needle of the sewing machine.

Figure 6 is an elevational view illustrating an assembly set-up for the sewing machine and attachment for foot control of the sewing operation.

Figure 7 is a vertical sectional detail of the clutch mechanism employed in the drive of the operating cam.

Figure 8 is a perspective view of a piece of work stitched with the aid of the attachment.

Figure 9 is a diagrammatic view of the control circuit employed in the setup of Figure 6.

Figure 10 is an enlarged elevational view of the clutch and air controlling solenoid.

Figure 11 is an elevational view of the device of Figure 10 taken at right angles thereto.

Referring to the drawings, particularly Figures l, 2 and 3, the attachment is supported on a longitudinal base 1 presenting at the front a pair of spaced posts 2 and at the rear a pair of pivot lugs 3. Formed integral with one of the posts 2 and disposed intermediate the width of the base is a boss 4.

Mounted on the posts 2 is a guide rod 5 on which is slidably arranged a slide 6. The slide 6 has a sleeve portion 7 in which said guide rod 5 is received, and the opposite edge of said slide is supported in a guide 3.

Rotatably supported from the lugs 3 is a rock shaft 9 coupled through an arm 10 to a rocker arm or bar ll-adapted to-beconnected-by the bar 12 to the-feed mechanism of the sewing machine 13. Adjustably clamped on the rock shaft 9 is a rocker bar 14 of elongatedUformationwhich has a throw in accordance withthe'rock of the shaft") actuated 'by the feedmecha- -nism of the sewing machine-through-the rocker arm 11.

Supported on a stud shaft 15 journal-led in the boss 4 is a cam in-theform of a flat plate '16 having a generally spiral peripheral or camming surface '17. 'Set 'into thecam atthe'surface 17 is a sprocket chain 18 arrangedto have its pitch line on or-just below the surface 17, and the sprocket chain may be considered as being inclined in the camming surface. The chain 18 is adapted to be engaged by a driving sprocket-wheel 19 carried by the slide 6 to rotate the cam as hereinafter more fully described,-while the roller 19 rolling on the cam surface 17 provides smooth cam rotation.

As seen particularly inFigure 3, theslide 6 has journalled therein a vertical shaft20 which carries a worm wheel or gear 21 and on which is mounted a roller 19 and a sprocket wheel 19 at a point above the slide. The roller and sprocket wheel are held to the shaft 20 by means of a large knurled nut 22 which clamps the sprocket againsta collar 23 when it is desired'that the sprocket rotate with the shaft 20, and which can be loosened to allow the sprocket to turn freely on the shaft.

As shown particularly in Figure 1, the slide 6 car- 'ries a transverse shaft 24 on which is mounted a worm 25 meshing withthe worm gear 21 to rotate the vertical shaft 20 on rotation of the transverse shaft 24. The

ends of the shaft'24 extend outwardly beyond the slide 6 and, as shown particularly in Figures 3 and 7, one end. carries a clutch mechanism generally designated at 26: throughwhich the reciprocating throw of the rocker bar 14 is translated totuni-direction rotation of the shaft .24, andthe other end of which carries a suitable friction brake mechanism26' riding on a drum 27'.

As shown in Figure 7, the particular clutch illustrated :comprises a rotor'27 fixed to the shaft 24 and provided with notches 28. Encirclingtherotor 27 is a ring 29 having aforkedprojection 30 which slidably receives the ring.

Thus rocking of the bar 14 upon rocking of the rock shaft 9 through the rockerarm 11 attached to the feed mechanism of the sewing machine 13, the shaft 24 is rotated. This rotation in turn is imparted through the worm 25' and worm gear. 21. to the verticalxshaft- 20 to rotate the sprocket wheel 19, the teeth of whichv engage withthe chain 18 .torrotate the cam .16 about the axis of its'shaft 15, while .the roller19'running on the cam surface 17 provides smooth cam movement.

Connected to the slide 6 is a chain or cable 32 which passes over a sprocket 33' andthroughan opening 34 in the base 1 carrying a weight 35 acting to draw the slide towards the cam, maintaining the sprocket wheel in firm mesh with the chain18 at the periphery of the. cam 16 and the roller 19 firmly against the surface 17.

For smooth sliding movement ofthe slide 6 a series of ball-bearings or. rollers 36 are mounted within the .sleeve 7 to roll on the guide rod 5, as shown in Figure 3;

Carried by the slide 6 is an arcuate arm '37 carrying at its outer end a fiat bar 38 extending substantially parallel to the guide rod 5. Located adjacent the'end of the bar 38 is a pin 39 on which the work or fabric 40, herein shown as a bust cup, is adapted to be'impaled, as shown in 'Figure 5. The bar 38 carrying the work 40 "is adaptedto' slide in a guide 41imounted on *thebase42of"thesewing' machine 13' for movement towards and from the operating orstitching needle 43 of the machine.

To hold the work or fabric 40 in proper position during stitching an air tube 44 connected to a compressed air supply, indicated at 45 in Figure 6, through a suitable solenoid-operated air valve 46, shown diagrammatically in block form in Figures 6 to 11, through connecting flexible tubing, not shown, is placed over the pin 39 on top of the work. This tube 44 has its end cut on the bias to provide a discharge mouth 47 directing air outwardly generally on a radius of the work 40 in the direction of the sewing needle 43.

This air stream acts to hold the fabric down beneath the foot 48 of the sewing machine in a flattened condition for stitching, and a second air tube 49 connected to the air supply 45, in the same manner as the tube 44, has its mouth 50 arranged to direct an air fiow generally tangentially of the work '40 towards the stitching needle 43 to again smooth out the fabric in a flattened state for stitching, while allowing the fabric to conform against thepressure of the air to the configuration assumed on stitching.

The sewing machine .13 and its attachment may be employed as an isolated unit or may for instance be set up for assembly-line operation, as illustrated more-orless diagrammatically in Figure 6, in which the drive for the machine 13, located on the table 51, is obtained through a line shaft 52 and a suitable clutch mechanism illustrated at 53. The clutch mechanism is shown as adapted tobeoperated by a 'treadle 54 which'when depressed will connect the sewing machine to the line shaft 52. r V

With. reference toy-Figure 6, upon the treadle 54 being depressed the operating bar 55 operatively connects the shaft 52 tothe 'clut'ch mechanism 53. The operating bar 55 is maintained in its operative position by the latch bar 56 whose position is rigidly fixed by the energized solenoid'57. Energization of the solenoid 57 is obtained through an on-oif switch 58 located beneath the table' 51, and aplunger-operated micro-switch '59 connected in series therewith and with the solenoid 57, as shown in Figure 9.

The plunger-operated micro-switch 59 is mounted on a bracket 60 carried by the base l of the attachment and carries a roller 61 at the outer end of its plunger 62.

An arcuate cam block 63 is mounted on the undersurface of the cam 16 by means of clamping screws 64 and consequent stoppage of the sewing and'rotation of the. cam '16.

Figures 10' and 11 depict one particular form of the latch arrangement, but, it-will be appreciated that it formsno part of'the'present invention and that the clutch latching-in mechanism and air valve maybe varied as desired. With reference to Figures 10 and 11, the solenoid 57 is pivotally connected to a lever 66, which when the solenoid is energized, causes the projection 66' to engage a cooperating projection 67 which is part of a pivotal arm .67. This pivotal arm is pivoted to a pivot lug 56' which is rigidly connected to the latch bar 56. A plate 68 is riveted to the lug '56 sothat at its outer end it maysupportthe-spring 68 whose lower end is mounted onthe free end of the armv 67. It will be seen that when the, solenoid 57 is deenergized, the proiection 66' of-the lever arm 66 ismfree .tomoverupwardly. During the deenergization periodiflthe latch bar is loosely held in its position so that the operating .bar,. 55=may disengage the clutch mechanis'm'53 and the driving shaft 52. Upon energization of the solenoid 57 the end of the lever member 66 connected to the solenoid moves upwardly, hence the projection 66 moves downwardly to engage the projection 67 which through its connections rigidly fixes the position of the latch bar 56, the spring 68 urging the projection 66' and 67 into contact. This operation is coincident with the opening and closing of the air valve 46 by the action of the lower surface of the projection 66' upon the roller member 69 which is mounted in the valve arm 46.

In the operation of the sewing machine and its attachment, the operator first switches on the device at the switch 58 and depresses the treadle 54 after having impaled the work or fabric 4t), herein shown as a circular fabric, at its centre on the pin 39, the air tube 44 having been placed over the pin, as illustrated in Figure 6.

Upon depression of the treadle the clutch 53'': will be operated to couple the machine to the line shaft 52 and with the cam 16 rotated to its starting position so that the sprocket wheel 19 of the slide engages the chain 18 on the cam at its starting end 7d, the cam block 63 carried on the underside of the cam 16 will be clear of the roller 61 of the micro-switch 59, so that the solenoid 57 will be energized to operate the latch bar 56 to maintain the clutch 53 in the latched-in position following removal of the pressure on the treadle 54. At the same time the solenoid 57 will operate to open the air valve 4-6, allowing a stream or jet of compressed air to be delivered out of the air tubes 44 and 4Q.

At the beginning of the operation, the sprocket wheel 19 of the slide 6 engages the chain lit at the initial or starting point 76 so that the needle 43 of the sewing machine will begin its stitching adjacent the centre of the work 40. When the sewing operation is completed, the slide 6 will have moved to its extreme left hand position as shown in Figure 1, the roller 19 displacing the canmaing surface 17 of the cam 16 under the action of the Weight 35.

As the stitching continues the rocker arm llll, connected to the feed mechanism of the sewing machine l3, will rock the rock shaft 9, imparting a throw to the rocker bar 14, driving the sprocket wheel 19 and roller 19' through the clutch 26 and worm members 21 and 25, as previously explained.

A uniform rate of stitching of the machine 13 will thus provide a substantially uniform or constant speed of rotation of the sprocket wheel 19. This sprocket wheel in turn, meshing with the sprocket chain 18, will provide a substantially uniform peripheral velocity to the earn as it meshes with the sprocket wheel and is driven thereby to rotate about the axis of its shaft 15.

The reaction of the cam as it is rotated by the sprocket wheel is to move the slide 6 longitudinally of its guides in accordance with the configuration of the peripheral or camming surface 17. Thus by having the cam 16 relatively large and having an accurately predetermined spiral-like cumming surface, a refined and controlled movement is imparted to the slide to move it in a direction to progressively withdraw the fabric or work ill from the stitching needle 43 at a rate progressively decreasing with the increase of distance from the stitching needle.

This non-linear velocity of the slide 6 thus results in the provision of a spiral stitching 71 on the work it? in which the radial spacing between the successive convolutions of the spiral are precisely uniform or constant, with the controlled movement of the slide compensating for the increasing length of each successive convolution. After stitching has progressed to the point where the cam is rotated to bring the cam block 63 into engagement with the roller 61 of the switch 5 2', switch 59 is opened, breaking the circuit to the solenoid 57, releasing .the clutch 53 and opening the air valve 46, stopping the operation of the sewing machine.

If further stitching is required beyond this point the operator may depress the treadle 54 and carry on the stitching as long as the treadle is depressed or until the cam block 63 clears the roller 61, in which case the solenoid 57 will again be energized.

During the stitching, with the air valve 46 open, the air stream issuing from the tube 44 will urge the portion of the fabric approaching the stitching needle 43 outwardly from the pin 39 so that it will be radially extended at this point, preventing gathers between the rows of spiral stitching. At the same time air from the tube 49, directing air tangentially of the work at the edge thereof being stitched, will tend to maintain the work flat for stitching, the air streams or jets however allowing the fabric to conform to the natural configuration assumed on stitching and maintaining the fabric free from any rigid elements which would bar the natural feed of the fabric beneath the stitching needle or which would tend to contact and soil the fabric.

When the cam has rotated to the point where its block 63 breaks switch 59, de-energizing the machine, the work is normally removed and the attachment re-set by loosening the nut 22, allowing the weight 35 to retract the slide to its right-hand starting position, so that its sprocket wheel 19 will again engage the sprocket chain 18 at the starting point '70 with the cam rotated to its initial or starting position.

It will be understood that in place of the sprocket chain 18 the camming surface l7 of the cam can be formed with indentations or teeth actually integral therewith, or any other form of positive drive, between the rotating member on the slide 6 and the cam, may be employed to obtain the uniform peripheral cam speed, while giving a continually changing angular velocity to the cam about its axis.

To provide a fine adjustment of the stitching and to compensate for differences in the shapes of the cups or cones being stitched, the rock bar 14 can be adjusted on the rock shaft 9 to lie inclined thereto and alter the throw of the clutch ring 29 as the forked extension 30 slides along the bar 14, and hence provide a further refined control of the sprocket wheel drive to provide the desired compensation.

What we claim as our invention is:

1. in a device for spiral stitching adapted for use with a sewing machine, a slide adapted to carry a fabric to he stitched, a cam acting on said slide to move same, and means carried by said slide and engaging the camming surface of said cam to displace said camming surface with constant average velocity at its point of contact with the slide.

2. In a device for spiral stitching adapted for use with a sewing machine, a slide adapted to carry a fabric to be stitched, a rotatable cam rotatable about a fixed axis and having a peripheral camming surface receding from said axis around the cam, a rotating drive member carried by said slide and rolling on said camming surface to rotate said cam and displace said slide, and drive means adapted to connect said device to a sewing machine for rotating said drive member.

3. In a device for spiral stitching adapted for use with a sewing machine, a slide, means guiding said slide for reciprocal movement, a cam rotatable about a fixed axis and having a spiral-like camming surface receding from said axis around the cam, rotating drive member carried by said slide and running on said camming surface to rotate said cam through a part revolution and displace said slide, and drive means adapted to be congected to a sewing machine to drive said rotating mem- 4. in a device for spiral stitching adapted for use with a sewing machine, a frame, a slide reciprocally mounted on said frame, a cam having a generally spiralling peripheral cam surface rotatably supported on a fixed axis with said cam surface continuously receding from said axis for an extent of the periphery of said cam,

ing with said chain.

6. In a device for spiral stitching adapted for use with .a sewing machine having a needle and feed mechanism, a support frame, a siide reciprocally mounted on said frame to carry work to be stitched towards and from said needle, a cam having a planar spiral-like peripheral camming surface supported on said frame to rotate about a fixed axis with said camming surface receding from said axis around the cam, a rotatable driving member carried by said slide and running on said spiral-like camming surface to rotate said cam through a portion of a revolution effecting displacement of said slide, and means for driving said rotatable driving-member.

7. In a device for spiral stitching adapted for use with .a sewing machine having a needle and feed mechanism, a support structure, a slide reciprocally mounted on said support structure for movement towards and from the needle of a sewing machine, a cam carrried by said support and having a spiral-like camming formation rotatable about a fixed pivot and lying in a plane perpendicular to the axis of said pivot, a rotating drive member carried by said slide and engaging said camming formation, means urging said drive member against said camming formation, and means for driving said drive member adapted to be connected with a feed mechanism of a sewing machine.

8. A device as claimed in claim 7 in which said driving means comprises a longitudinal rocker member, a worm drive carried by said slide and rotating said drive member, and a clutch mechanism operatively connected between said worm drive and said rocker member and including a rocker arm engaging the aforesaid rocker member and freely slidable longitudinally thereof.

9. A device as claimed in claim 7 in which said drive member comprises a toothed wheel and the camming formation of said cam is provided with means with which said toothed wheel is adapted to mesh.

10. A device for spiral stitching adapted for use with a sewing machine having'a needle and a feed mechanism, comprising a frame, a longitudinal guide on said frame,

a slide reciprocal on said guide to move towards and from the needle of a sewing machine, a shaft journalled on said slide, a worm drive carried by said slide and adapted to rotate said shaft, a sprocket wheel mounted on said shaft, a rock shaft mounted on said frame, means adapted to couple said rock shaft to the feed mechanism of a sewing machine, a longitudinal rock bar adjustably secured to said rock shaft and having a throw corresponding to the rocking of said rock shaft, a uni-directional clutch device carried by said slide comprising a reciprocal clutch member slidably engaging said rock bar to be reciprocated thereby while sliding therealong, a

clutch member connected to said worm drive and means to impart uni-directional rotative movement to said latter clutch member from said reciprocal clutch member, a cam rotating in a fixed journal carried by said frame and'having a spiral-like camming" surface provided with means with which said sprocket wheel is adapted to mesh to rotate said cam on rotation of said sprocket, and

means acting on said slide to hold said sprocket in meshing'relation with said camming surface.

.said"micro-switchupon'a predetermined degree of cam =-rotation, said-micro switchbeing adapted to be connected in an electrical circuit controlling operation of a sewing machine with which the deviceisused to interrupt sewing machine operation, and cam rotation when operated by said cam. 1 t

12. In a device for spiral stitching adaptedfor use with a sewing machine, a slide having a pin onwhich work to be stitched is adapted to be impaled, arcam having a spiral-like camming surface, a rotating member carried by said slide and running on said camming surface to rotate said cam and displace said slide, drive means adapted to be connected to a sewing machine to drive said rotating member, and means to maintain workimpaled on said pin, said latter means comprising a movable tube adapted to be connected to a compressed air supplyand sleeved on said pin over an impaled piece of work and having a nozzle arrangement to direct a stream of compressed air outwardly from said pin.

13. A device as claimed in claim 12 in which a second tube is arranged adjacent theneedle of a sewing machine to direct a stream of compressed air on workbeing stitchedgenerally transversely of the aforesaid stream adjacent the point of stitching.

14. A device adapted for use witha sewingmachine for effecting spiral stitching comprising a slide, apin carried by said slide and on which work to be stitched is adapted to be impaled, means for moving said slide relative to the needle of a sewing machine, and nozzle means arranged to direct a stream of air on work impaled on said pin in adirection away from thepin to tension the fabric away from the pin, said nozzle means comprising a movable tube sleeved on said pin to be carried by said slide and having its end cut on a bias to form amouth opening to one side of the pin.

15. A device adapted for use with a sewing machine for effecting spiral stitching comprising a slide, a pincarried by said slide and on which work to be stitched is adapted to be impaled, means for moving said slide relative to the needle of a sewing machine, and nozzle means arranged to direct air away from said pin generally towards the needle of a sewing machine to tension the work' away from the pin at the point of stitching.

16. A device as claimed in claim 15in which a second nozzle is arranged to direct the stream of 'air in a. direction substantially transversely of the direction of the air stream delivered by the first nozzle to impinge on the fabric adjacent the point of stitching to spread same for stitching. g

17. In a device for spiral stitching adapted for use with a sewing machine having a needle and feed mechanism, a slide adapted to carry a piece of fabric for movement relative to said needle, a cam in the form of agenerally fiat member mounted to rotate about a fixed axis, said cam having a peripheral camming surface continuously receding from said axis for a portion .of the cam periphery, means carried by said slide to engage said camming surface and to operate said cam, said cam displacing said slide through the extent of its movement'for spiral stitching in an accurately predetermined manner upon rotation of said cam through a portion of a revolution.

18. A device as claimed in claim 17 in which the means for operating said cam comprises a rotating driving toothed member meshing with. a cooperating means at the camming surface of said cam and a roller rolling on said camming surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,466,486 Schloss Aug. 28, 1923 2,423,996 Rubel JulylS, 1947 2,437,624 Sutker Mar. 9, 1948 2,521,085 Ogden Sept. 5, 1950 2,551,261 Gensheimer May 1, 1951 2,674,963 Guide Apr. 13, 1954 2,674,964 Guide Apr. 13, 1954 

